Nine students were sent to the hospital Friday morning after a school bus was involved in a three-vehicle accident on North Whidbey.

A truck towing an excavator was traveling on East Sleeper Road and crashed into a Honda Pilot, which was carrying two elementary-school children, according to the Washington State Patrol.

The force of the collision propelled the Honda Pilot into the rear end of a school bus, which was carrying 20 students and had just retracted its stop paddle after picking up two children.

According to the State Patrol, nine children on the bus were transported to WhidbeyHealth Medical Center with minor injuries and for observation.

The occupants of the Honda did not sustain injuries. The driver of the truck was cited for excessive speed for the icy conditions of the road, the State Patrol reported.

School officials have been concerned about bus safety in recent years.

Officials implemented a program that places cameras on buses to catch drivers who illegally pass stopped buses that have paddles out. So far, only two buses have been outfitted with the cameras, but up to four more are planned for later this year.

The bus involved in the crash is not one of those outfitted with a camera.

Four citations of people illegally passing school buses have been issued this year.